Thin film magnetic head recessed partially into substrate and including plantarization layersi

ABSTRACT

A combination type thin film magnetic head including an inductive type thin film writing magnetic head and a magnetoresistive type thin film reading magnetic head successively stacked on a substrate is manufactured in the following manner. A recessed portion is formed in a surface of the substrate  21 , a first insulating layer  26 , a first magnetic layer  27  and a thin film coil  29  isolated by a second insulating layer  28 . A pole portion  32  is formed such that it is opposed to a pole portion of the first magnetic layer  27 , and a second magnetic layer  34  is formed such that the third magnetic layer is brought into contact with the pole portion and is coupled with the first magnetic layer  27  at a position remote from in air bearing surface. Then, a MR reproducing element  40  embedded within a shield gap layer  35  is formed, and a third magnetic layer  37  is formed on the shield gap layer  35 . By controlling a thickness of the first insulating layer, the throat height of the inductive type thin film magnetic head can be adjusted independently from the MR height of the magnetoresistive type thin film magnetic head. Therefore, the throat height, apex angle and MR height can be formed accurately, while the throat height can be controlled without destroying a good balanced condition between the throat height and the MR height.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a thin film magnetic head and amethod of manufacturing, the same, and more particularly to acombination type thin film magnetic head constructed by stacking aninductive type writing thin film magnetic head and a magnetoresistivetype reading thin film magnetic head.

[0003] 2. Description of the Related Art

[0004] Recently a surface recording density of a hard disc device hasbeen improved, and it has been required to develop a thin film magnetichead having an improved performance accordingly. A combination type thinfilm magnetic head is constructed by stacking an inductive type thinfilm magnetic head intended for writing and a magnetoresistive type thinfilm magnetic head intended for reading on a substrate, and has beenpractically used. In general, as a reading magnetoresistive element, anelement utilizing anisotropic magnetoresistive (AMR) effect has beenused so far, but there has been further developed a GMR reproducingelement utilizing a giant magnetoresistive (GMR) effect having aresistance change ratio higher than that of the normal anisotropicmagnetoresistive effect by several times.

[0005] In the present specification, elements exhibiting amagnetoresistive effect such as AMR and GMR reproducing elements aretermed as a magnetoresistive reproducing element or MR reproducingelement.

[0006] By using the AMR reproducing element, a very high surfacerecording density of several gigabits/inch² has been realized, and asurface recording density can be further increased by using the GMRelement. By increasing a surface recording density in this manner, it ispossible to realize a hard disc device which has a very large storagecapacity of more than 10 gigabytes.

[0007] A height (MR Height: MRH) of a magnetoresistive reproducingelement is one of factors which determine a performance of a reproducinghead including a magnetoresistive reproducing element. The MR height MRHis a distance measured from an air bearing surface on which one edge ofthe magnetoresistive reproducing element is exposed to the other edge ofthe element remote from the air bearing, surface. During a manufacturingprocess of the magnetic head, a desired MR height MRH can be obtained bycontrolling an amount of polishing the air bearing surface.

[0008] At the same time, the performance of the recording magnetic headis also required to be improved in accordance with the improvement ofthe performance of the reproducing magnetic head. In order to increase asurface recording density, it is necessary to make a track density on amagnetic record medium as high as possible. For this purpose, a width ofa write gap at the air bearing surface has to be reduced to a valuewithin at range from several micron meters to several sub-micron meters.In order to satisfy such a requirement, the semiconductor manufacturingprocess has been adopted for manufacturing the thin film magnetic head.

[0009] One of factors determining the performance of the inductive typethin film writing magnetic head is a throat height TH. This throatheight TH is a distance of a pole portion measured from the air bearingsurface to an edge of an insulating layer which serves to separate athin film coil from the air bearing surface. It has been required toshorten this distance as small as possible. The reduction of this throatheight is also decided by an amount of polishing the air bearingsurface.

[0010] Therefore, in order to improve the performance of the combinationtype thin film magnetic head having the writing inductive type thin filmmagnetic head and reading magnetoresistive type thin film magnetic headstacked one on the other, it is important that the recording inductivetype thin film magnetic head and reproducing magnetoresistive type thinfilm magnetic head are formed with a good balance.

[0011] FIGS. 1-3 show successive steps for manufacturing a conventionalstandard thin film magnetic head, in these drawings A depicts across-sectional view of a substantial portion of the head and Brepresent a cross sectional view of a pole portion. Moreover, FIGS.10-12 are a cross sectional view of a substantial portion of thecompleted thin film magnetic head, a cross sectional view of the poleportion, and a plan view of the substantial portion of the thin filmmagnetic head, respectively. It should be noted that the thin filmmagnetic head is of a combination type in which the inductive type thinfilm magnetic head for writing, is stacked on the reproducing MRelement.

[0012] First of all, as shown in FIG. 1, an insulating layer 2consisting of, for example alumina (Al₂O₃) is deposited on a substance Imade of a non-magnetic and electrically insulating material such asAlTiC and having a thickness of about 5-10 μm.

[0013] Next, as shown in FIG. 2, a bottom shield magnetic layer 3 whichprotects the MR reproduction element of the reproducing head from theinfluence of an external magnetic field, is formed with a thickness of 3μm.

[0014] Afterwards, as shown in FIG. 3, after depositing an insulatinglayer 4 of thickness 100-150 nm serving as a shield gap layer bysputtering alumina, a magnetoresistive layer 5 made of a material havingthe magnetoresistive effect and constituting the MR reproduction elementis formed on the shield gap layer with a thickness of several tens nanometers and is then shaped into a given pattern by the highly precisemask alignment.

[0015] Then as shown in the FIG. 4, an insulating layer 6 is formed suchthat the magnetoresistive layer 5 is embedded within the insulatinglayers 4 and 6.

[0016] Next, as shown in the FIG. 5, a magnetic layer 7 made of atpermalloy is formed with a film thickness of 3 μm. This magnetic layer 7has not only the function of the upper shield layer which magneticallyshields the MR reproduction element together with the above describedbottom shield layer 3, but also has the function of one of poles of thewriting thin film magnetic head. Here, the magnetic layer 7 is called afirst magnetic layer by taking into account the latter function.

[0017] Then, after forming a write gap layer 8 made of a nonmagncticmaterial such as alumina and having a thickness of about 200 nm on thefirst magnetic layer 7, a second magnetic layer 9 made of a materialhaving a high saturation magnetic flux density such as permalloy (Ni:50wt %, Fe:50 wt %) and nitride iron (FeN) is formed with a desired shapeby the highly precise mask alignment. The second magnetic layer 9 havingformed into a given pattern is called a pole chip, and a track width isdetermined by a width W of the pole chip. Therefore, in order to realizea high surface recording density, it is necessary to decrease the widthW.

[0018] In this case, a dummy pattern 9′ for coupling the bottom pole(first magnetic layer) with the top pole (third magnetic layer) isformed simultaneously. Then, a through-hole can be easily formed bypolishing or chemical mechanical polishing (CMP).

[0019] In order to prevent an effective width of writing track frombeing widened, that is, in order to prevent a magnetic flux from beingspread at the bottom pole upon the data writing, portions of the gaplayer 8 and bottom pole (first magnetic layer) 7 are etched by an ionbeam etching such as ion milling. The structure after this process isshown in FIG. 5. This structure is called a trim structure and thisportion serves as a pole portion of the first magnetic layer.

[0020] Next, an shown in FIG. 6, after forming an insulating layer, forexample alumina film 10 with a thickness of about 3 μm, the wholesurface is flattened by, for instance CMP.

[0021] Subsequently after forming an electrically insulating photoresistlayer 11 into at given pattern by the mask alignment of high precision,a first layer thin film coil 12 made of, for instance a copper is formedon the photoresist layer 11.

[0022] Continuously, as shown in FIG. 7, after forming an electricallyinsulating photoresist layer 13 on the thin film coil 12 by the highlyprecise mask alignment, the photoresist layer is sintered at atemperature of for example 250-300° C.

[0023] In addition, as shown in FIG. 8, a second layer thin film coil 14is formed on the flattened surface of the photoresist layer 13. Next,after forming a photoresist layer 15 on the second layer thin film coil14 with the highly precise mask alignment, the photoresist layer isflattened by performing the sintering process at a temperature of, forexample 250° C.

[0024] As described above, the reason why the photoresist layers 1, 13and 15 are formed by the highly precise mask alignment process, is thatthe throat height TH and MR height MRH are defined on the basis of aposition of the edges of the photoresist layers on a side of the poleportion.

[0025] Next, as shown in FIG. 9, a third magnetic layer 16 made of, forexample a permalloy and having a thickness of 3 μm is selectively formedon the second magnetic layer (pole chip) 9 and photoresist layers 11, 13and 15 in accordance with a desired pattern. This third magnetic layer16 is coupled with the first magnetic layer 7 at a rear position remotefrom the pole portion through the dummy pattern 9′, and the thin filmcoil 12, 14 passes through a closed magnetic circuit composed of thefirst magnetic layer and the second and third magnetic layers.

[0026] Furthermore, an overcoat layer 17 made of alumina is deposited onthe exposed surface of the third magnetic layer 16. Finally, a sidesurface of assembly at which the magnetoresistive layer 5 and gap layer8 are formed is polished to form an air bearing surface (ABS) 18 whichis to be opposed to the magnetic record medium. During the formation ofthe air bearing surface 18, the magnetoresistive layer 5 is alsopolished to obtain a MR reproducing element 19. In this way, the abovedescried throat height TH and the MR height MRH are determined. Thiscondition is shown in FIG. 10. In an actual thin film magnetic head,electric conductors and contact pads for performing the electricalconnection to the thin film coils 12, 14 and MR reproduction element 19arc formed, but they are not shown in the drawings.

[0027] As shown in FIG. 10, an angle θ (apex angle) between a line Sconnecting side corners of the photoresist layers 11, 13, 15 forisolating the thin film coils 12,14 and the upper surface of the thirdmagnetic layers 16 is an important factor for determining theperformance of the thin film magnetic head together with the abovedescribed throat height TH and MR height.

[0028] Moreover, as shown in the plan view of FIG. 12, the width W ofthe second magnetic layer 9 and a pole portion 20 of the third magneticlayer 16 is small. Since the width of the track recorded on the magneticrecord medium is defined by this width W, it is necessary to narrow thiswidth as small as possible in order to achieve a high surface recordingdensity. It should be noted that in this figure, for the sake ofconvenience, the thin film coils 12, 14 are shown concentrically.

[0029] In the method of manufacturing, the conventional thin filmmagnetic head, there is a problem that after forming the thin film coil,the top pole could not he formed precisely on the protruded coil sectioncovered with the insulating photoresist especially along the inclinedsurface (apex). That is to say, in the known method, the third magneticlayer is formed by first plating a magnetic material such is permalloyon the mountain shaped coil with a height of about 7-10 μm, by applyingthe photoresist with a thickness of 3-4 μm, and by shaping the magneticlayer into a given pattern by means of the photolithography technology.

[0030] Now it is assumed that the photoresist formed on the protrudedcoil portion into a given pattern should have a thickness of 3 μm ormore, a thickness of the photoresist at a bottom or root of the inclinedportion would amount to about 8-10 μm.

[0031] On the one hand, the top pole formed on the protruded coilportion having a height of about 10 μm as well as on the write gap layerformed on the flat surface should have a narrow portion in the vicinityof the edges of the insulating photoresist layers (for instance layers11 and 13 in FIG. 7) in order to realize a narrow track width.Therefore, it is necessary to form the pattern having a width of 1 μm byusing the photoresist film having a large thickness of 8-10 μm.

[0032] However, it is extremely difficult to form the photoresist filmhaving a thickness of 8-10 μm into a pattern having a width of about 1μm, because upon the light exposure in the photolithography, a patterndeformation might occur due to reflection of light and resolution isreduced due to the thick photoresist layer. In this manner, it isextremely difficult to form a top pole defining precisely a narrow trackwidth by patterning.

[0033] Then, as is shown in the above explained conventional thin filmmagnetic head, in order to write data by means of the pole chip capableof forming the narrow track width, after forming the pole chip, the toppole chip formed to he connected to the pole chip. In other words, inorder to solve the above problem a divided structure is adopted, thatis, the pole chip for determining the track width and the third magneticlayer for introducing the magnetic flux.

[0034] However, the known thin film magnetic head, particularly therecording head formed as in the above manner still has the followingproblems.

[0035] (1) The throat height TH and MR height MRH are determined bytaking a position of the edge of the insulating layer isolating the thinfilm coil on a side of the pole portion as a reference position, but theinsulating layer is usually made of an electrically insulating organicphotoresist layer and is liable to be deformed by heat. During theformation of the thin film coil, the insulating layer might be deformedby the heating treatment at about 250° C., and a pattern size of theinsulating layer changes, and the throat height TH and MR height MRHmight be deviated from desired design values. As explained above, thephotoresist layer has a very large thickness at this portion, and thusthe influence due to the deviation of pattern is also large.

[0036] (2) In the above mentioned combination type thin film magnetichead, it is important to attain a good balance between the writing thinfilm magnetic head and the reading MR element. However, in theconventional combination type thin film magnetic head, for instance whenthe air bearing surface 18 is polished such that the throat height THcan be formed to a desired design value, the MR height MRH of the MRreproducing element might be also changed, and when the air bearingsurface is polished to obtain the MR height MRH having a desired designvalue, the throat height TH might be deviated from a desired value inthis manner, it is difficult to provide a combination type thin filmmagnetic head having desired characteristics.

[0037] (3) In the known method of manufacturing the combination typethin film magnetic head since the throat height TH of the writing thinfilm magnetic head and the MR height MRH of the reading MR element havea fixed relationship there is another problem that it could not respondquickly to various needs of users. That is to say, if it is required toprovide a combination type thin film magnetic head, in which a MR heightMRH is identical with that of the so far manufactured heads, but athroat height TH is smaller than that of the so far manufactured heads,or if it is required to provide a combination type thin film magnetichead, in which a MR height MRH is smaller than that of the so farmanufactured heads although a throat height TH is equal to that of theso far manufactured heads, such requirements could I not be fulfilledonly by adjusting a polishing amount of the air bearing surface.Therefore, the manufacturing process has to be reviewed from thebeginning, and thus such a request could be responded quickly.

[0038] (4) Since the pole chip and top pole are contacted with eachother via a small contact area, and they are brought into contact witheach other at right angles, the magnetic flux is liable to be saturatedat the contact portion, and therefore a satisfactorily high writingcharacteristic could not be obtained.

[0039] (5) Since a positional relation between the pole chip and the toppole is determined bit the alignment of the photoresist layer, a centerline of the pole chip viewed from the air bearing surface might deviatelargely from a center line of the top pole. Then, the data writing mightbe carried out by means of the magnetic flux leaked from the top pole,and the effective tract width might be increased and data might beerroneously recorded on an adjacent track.

SUMMARY OF THE INVENTION

[0040] It is an object of the present invention to provide a thin filmmagnetic head, in which the above mentioned various problems can besolved advantageously, a pattern size of an insulating layerconstituting a reference positional with respect to an air bearingsurface is not deviated by a heating treatment during the formation of athin film coil, and therefore a throat height TH having a desired designvalue can be attained stably.

[0041] It is another object of the invention to provide a thin filmmagnetic head, in which a contact area between a pole chip and a toppole can be effectively increased to completely or substantiallycompletely avoid a saturation of a magnetic flux at a pole portion.

[0042] It is another object of the invention to provide a thin filmmagnetic head, in which an increase in an effective track width and adecrease in a manufacturing yield can be avoided.

[0043] It is another object of the invention to provide a method ofmanufacturing such thin film magnetic heads having excellentcharacteristics in an efficient and accurate manner.

[0044] It is another object of the invention to provide a method ofmanufacturing a combination type thin film magnetic head, in which apattern of an insulating layer defining a positional reference withrespect to an air bearing surface is not deviated by a heating treatmentduring the formation of a thin film coil to obtain the throat height TH,apex angle θ and MR height MRH having desired design values, and thethroat height TH and MR height MRH can be controlled independently fromeach other, while a good balanced condition between the throat heightand the MR height is not destroyed so that users requests for theseheights can be satisfied promptly.

[0045] According to a first aspect of the invention, a thin filmmagnetic head comprises:

[0046] a first magnetic layer having a pole portion;

[0047] a second magnetic layer having a pole portion which is to beopposed to a magnetic record medium and defines a width of recordtracks, and an end surface which constitutes an air bearing surfacetogether with an end surface of said pole portion of said first magneticlayer;

[0048] a third magnetic layer which is brought into contact with saidsecond magnetic layer on a side opposite to said first magnetic layerand is magnetically coupled with said first magnetic layer at a portionremote from said air bearing surface;

[0049] a gap layer made of a non-magnetic material and being interposedbetween the pole portion of the first magnetic layer and the poleportion of the second magnetic layer at least at the air bearingsurface;

[0050] a thin film coil having a portion which is arranged between saidfirst magnetic layer and said second and third magnetic layers withinterposing an insulating layer therebetween to generate a writingmagnetic flux for the magnetic record medium; and

[0051] a substrate which supports said first, second and third magneticlayers, gap layer, insulating layer and thin film coil;

[0052] wherein said second magnetic layer is extended up to a rearregion beyond said pole portion to form an extended rear portion whichis brought into contact with the third magnetic layer, and a part ofsaid first magnetic layer except for at least said pole portion and thethin film coil isolated by said insulating layer are embedded within arecessed portion formed in the substrate.

[0053] In a preferable embodiment of the thin film magnetic headaccording to the first aspect of the invention, a width of the rearportion of said second magnetic layer is larger than that of the poleportion of the second magnetic layer constituting the pole chip. In thiscase, a width of the rear portion may be gradually increased. Thisexpanded angle of the rear portion of the second magnetic layer ispreferably set to 30-180°.

[0054] Moreover, in a preferable embodiment of the thin film magnetichead according to the first aspect of the invention, said secondmagnetic layer is made of a material having a high saturation magneticflux density such as a permalloy.

[0055] Furthermore, a portion of the first magnetic layer which isopposed to the pole portion of the second magnetic layer via the gaplayer may preferably be protruded toward the second magnetic layer, anda width of the protruded portion is substantially equal to a width ofthe pole portion of the second magnetic layer. The protruded structureof the first magnetic layer may be preferably formed by etching, whilethe pole portion of the second magnetic layer is used as a mask.

[0056] In another preferable embodiment of the thin film magnetic headaccording to the first aspect of the present invention, the thin filmmagnetic head is constructed as a combination type thin film magnetichead by arranging a magnetoresistive type reproducing element forreading on is surface of the third magnetic layer opposite to thesurface which is brought into contact with said second magnetic layersuch that an end surface of the reproducing element is exposed on theair bearing surface.

[0057] According to a second aspect of the invention, a method ofmanufacturing a thin film magnetic comprises:

[0058] the step of forming a recessed portion in a surface of asubstrate;

[0059] the step of forming a first insulating layer on the surface ofthe substrate including a surface of the recessed portion;

[0060] the step of forming a first magnetic layer having a pole portionon at least a part of the surface of the substrate on which said firstinsulating layer is formed;

[0061] the step of forming a thin film coil within the recessed portionsuch that the thin film coil is isolated by a second insulating layer;

[0062] the step of forming a gap layer on at least said pole portion ofthe first magnetic layer as well as on a surface of said secondinsulating layer after making said first magnetic layer and secondinsulating layer to have a coplanar surface;

[0063] the step of forming a second magnetic layer on said gap layersuch that the second magnetic layer extends over the pole portion of thefirst magnetic layer as well as over a rear region beyond the poleportion;

[0064] the step of forming a third magnetic layer such that the thirdmagnetic layer is brought into contact with the second magnetic layerand is brought into contact with said first magnetic layer at a rearportion remote from an air bearing surface; and

[0065] the step of forming the air bearing surface to be opposed to amagnetic record medium by polishing said substrate, pole portions ofsaid first and second magnetic layers and gap layer sandwiched by thesepole portions while an edge of the recessed portion formed in thesubstrate is used as a positional reference.

[0066] In a preferable embodiment of the method of manufacturing thethin film magnetic head according to this second aspect of theinvention, upon forming, said second magnetic layer, a width of the rearportion thereof beyond the pole portion is gradually increased. In thiscase, this expanded angle may be preferably set to 30-180°.

[0067] In another preferable embodiment of the method of manufacturingthe thin film magnetic head according to the second aspect of theinvention, after forming said second magnetic layer, the pole portion ofsaid first magnetic layer is etched while the pole portion of the secondmagnetic layer is used as a mask. This etching may be carried out suchthat a part of a thickness of the first magnetic layer is removed or maybe conducted to remove the first magnetic layer over its wholethickness.

[0068] Moreover, in another preferable embodiment of the method ofmanufacturing a thin film magnetic head according to the second aspectof the substrate comprises:

[0069] the step of forming a photoresist layer selectively on a part ofthe surface of the substrate at which the recessed portion is to beformed;

[0070] the step of forming a metal or metal compound layer constitutinga mask by a plating while said photoresist layer is used as a mask;

[0071] the step of forming a mask by removing said photoresist layer,said mask having an opening, corresponding to the recessed portion to beformed; and

[0072] the step of forming the recessed portion in the surface of thesubstrate by a reactive ion etching through the opening.

[0073] In this case, the reactive ion etching may be conducted by using,as a reactive gas, a fluorine series gas such as CF₄ and SF₆ or achlorine series gas such as BCl₁ and Cl₂ or one of these gas dilutedwith an oxygen or an inert gas.

[0074] Before forming the mask made of metal or metal compound, aninsulating layer may be formed on the substrate. Then, after forming therecessed portion by the etching, said mask made of metal or metalcompound may be removed by etching while said insulating layer is usedas an etching stopper. It is a matter of course that said mask made ofmetal or metal compound may be remained.

[0075] The reactive ion etching can form the deep recessed portionhaving a depth not less than 5 μm in an accurate manner. In this case,an inclination angle of a side wall of the recessed portion may bepreferably set to 45-75°, particularly 55-65°. It should be noted thatthe thus formed recessed portion has a highly smooth inner wall.

[0076] In another preferable embodiment of the method of manufacturingthe thin film magnetic head according to the second aspect of thepresent invention, a magnetoresistive type reproducing element forreading is formed on said third magnetic layer such that the reproducingelement is electrically isolated and magnetically shielded to constructthe thin film magnetic head as a combination type thin film magnetichead.

[0077] Upon manufacturing, such a combination type thin film magnetichead, before forming the first magnetic layer, a first shield layer foreffecting a magnetic shield on the substrate, a magnetoresistivematerial layer is formed such that this layer is embedded within aninsulating layer, then said first magnetic layer which also serves as asecond shield is formed, and during the polishing process for formingthe air bearing surface, said first shield layer as well as saidmagnetoresistive material layer are polished to form themagnetoresistive type reproducing element whose end surface is exposedon the air bearing surface.

[0078] Furthermore, according to a third aspect of the invention, amethod of manufacturing, a combination type thin film magnetic headhaving an inductive type writing thin film magnetic head and amagnetoresistive type reading thin film magnetic head for readingsuccessively stacked on a substrate comprises:

[0079] the step of forming, a recessed portion in a surface of asubstrate;

[0080] the step of forming a first insulating layer on an inner surfaceof the recessed portion as well as on a part of the surface of thesubstrate;

[0081] the step of forming a first magnetic layer on a surface of saidfirst insulating layer;

[0082] the step of forming a thin film coil within the recessed portionsuch that the thin film coil is isolated by a second insulating layer;

[0083] the step of forming a gap layer made of Li non-magnetic materialon surfaces of said first magnetic layer and second insulating layer;

[0084] the step of forming a second magnetic layer on a surface of saidgap layer such that the second magnetic layer is opposed to a poleportion of the first magnetic layer and is brought into contact withsaid first magnetic layer at a portion remote from an air bearingsurface;

[0085] the step of forming reading magnetoresistive layer on a surfaceof said second magnetic layer such that the magnetoresistive layer isembedded within a shield gap layer in an electrically isolated andmagnetically shielded manner;

[0086] the step of forming a third magnetic layer on said shield gaplayer; and

[0087] the step of forming the air bearing surface to be opposed to amagnetic record medium by polishing said substrate, pole portions ofsaid first and second magnetic layers, gap layer sandwiched by thesepole portions, shield gap layer, magnetoresistive layer and thirdmagnetic layer, while an edge of the recessed portion formed in thesubstrate is used as a positional reference;

[0088] wherein a throat height of the inductive type thin film writingmagnetic head is adjusted independently from a MR height of themagnetoresistive type reading thin film magnetic head by controlling athickness of said first insulating layer.

[0089] According to a fourth aspect of the present invention, a methodof manufacturing a combination type thin film magnetic head having, aninductive type writing thin film magnetic head and a magnetoresistivetype reading thin film magnetic head for reading stacked on a substratecomprises:

[0090] the step of forming at recessed portion in a surface of asubstrate;

[0091] the step of forming a first insulating layer on an inner surfaceof the recessed portion as well as on a part of the surface of thesubstrate;

[0092] the step of forming a first magnetic layer on said firstinsulating layer;

[0093] the step of forming a thin film coil within the recessed portionsuch that the thin film coil is isolated by a second insulating layer;

[0094] the step of forming a gap layer made of a non-magnetic materialon said first magnetic layer and second insulating layer;

[0095] the step of forming a second magnetic layer on said gap layer,said second magnetic layer having a pole portion which is opposed to apole portion of the first magnetic layer and a rear portion whichextends beyond the pole portion;

[0096] the step of forming a third magnetic layer which is brought intocontact with said second magnetic layer as well as with said firstmagnetic layer at a portion remote from an air bearing surface;

[0097] the step of forming in magnetoresistive layer on said secondmagnetic layer such that the magnetoresistive layer is embedded within ashield gap layer in an electrically isolated and magnetically shieldedmanner;

[0098] the step of forming a fourth magnetic layer on said shield gaplayer; and

[0099] the step of forming the air bearing surface to be opposed to amagnetic record medium by polishing said substrate, first, second andsecond magnetic layers, gap layer, shield gap layer, magnetoresistivelayer and fourth magnetic layer, while an edge of the recessed portionformed in the substrate is used as a positional reference;

[0100] wherein a throat height of the inductive type thin film writingmagnetic head is adjusted independently from a MR height of themagnetoresistive type reading thin film magnetic head by controlling athickness of said first insulating layer.

[0101] Further, according to a fifth aspect of the invention, a methodof manufacturing a combination type thin film magnetic head having aninductive type writing thin film magnetic head and a magnetoresistivetype reading thin film magnetic head for reading stacked on a substratecomprises:

[0102] the step of forming a first magnetic layer on a surface of asubstrate in accordance with a given pattern;

[0103] the step of forming a recessed portion in the surface of thesubstrate, while said first magnetic layer is used as a mask;

[0104] the step of forming a first insulating layer on an inner surfaceof the recessed portion;

[0105] the step of forming a reading magnetoresistive layer on saidfirst magnetic layer such that the magnetoresistive layer is embeddedwithin a shield gap layer;

[0106] the step of forming a second magnetic layer on said firstinsulating layer within said recessed portion as well as on said shieldgap layer;

[0107] the step of forming a thin film coil on said second magneticlayer within the recessed portion such that the thin film coil isisolated by a second insulating layer;

[0108] the step of forming a gap layer made of a non-magnetic materialon said second magnetic layer and second insulating layer;

[0109] the step of forming a third magnetic layer which is opposed tosaid second magnetic layer via said gap layer and is brought intocontact with said second magnetic layer at a portion remote from an airbearing surface, and

[0110] the step of forming the air bearing surface to be opposed to amagnetic record medium by polishing, said substrate, first magneticlayer, shield gap layer, second magnetic layer, gap layer and thirdmagnetic layer, while an edge of the recessed portion formed in thesubstrate is used as a positional reference;

[0111] wherein a throat height of the inductive type thin film writingmagnetic head is adjusted independently from a MR height of themagnetoresistive type reading thin film magnetic head by controlling athickness of said first insulating layer.

[0112] In the methods according to the above mentioned third to fifthaspects of the present invention, the throat height can be controlledindependently from the MR height by adjusting a thickness of the firstinsulating layer formed within the recessed portion. For instance, evenwhen the air bearing surface is polished such that the MR height becomesconstant, the throat height can be adjusted by controlling a thicknessof the first insulating layer. In this manner, the throat height can beformed to have a desired design value without loosing a good balancedcondition between the throat height and the MR height. Moreover, since athickness of the first insulating layer can be controlled very simply,various needs of users can be satisfied in a prompt manner. Bycontrolling a thickness of the first insulating layer within a range of0.2-0.8 μm, it is possible to adjust the throat height within asubstantially same range.

[0113] Furthermore, the apex angle is defined by an inclination angle ofthe side wall of the recessed portion, and this angle is not varied bythe high temperature process for photoresist layers. Therefore, it ispossible to obtain the apex angle having a desired design value.

[0114] In case of forming the recessed portion in the substrate, it ispreferable to conduct the reactive ion etching through the metal ormetal compound mask. By using the reactive ion etching, the deeprecessed portion having a depth not less than 5 μm, an inclination angleof a side wall of the recessed portion of 45-75°, particularly 55-65°,and a highly smoothed inner surface can be formed in an accurate andefficient manner.

[0115] The reactive ion etching for forming the recessed portion may beconducted by using, as a reactive gas, a fluorine series gas such as CF₄and SF₆ or a chlorine series gas such as BCT₃ and Cl₂ or one of thesegases diluted with an oxygen or inert gas.

[0116] Furthermore, before forming the mask made of metal or metalcompound, an insulating layer may be formed on the substrate. Then,after forming the recessed portion by the etching, said mask made ofmetal or metal compound may be removed by etching while said insulatinglayer is used as an etching stopper. It should be noted that said maskmade of metal or metal compound may be remained as in the methodsaccording to the fourth and fifth aspects of the present invention.

[0117] Moreover, in the method according to the above mentioned fourthaspect of the present invention, upon forming said second magneticlayer, a width of the rear portion beyond the pole portion may bewidened than the pole portion. In this case, it is preferable that therear portion of the second magnetic layer is gradually increased with anexpansion angle of 30-180°.

[0118] Also in the methods according to the third to fifth aspects ofthe invention, after forming the second magnetic layer, the pole portionof the first magnetic layer may be etched to constitute the trimstructure while the pole portion of said second magnetic layer is usedas a mask.

BRIEF DESCRIPTION OF THE DRAWINGS

[0119] FIGS. 1A, 1B-9A, 9B are cross sectional views showing successivesteps of a known method of manufacturing a conventional typicalcombination type thin film magnetic head;

[0120]FIG. 10 is a cross sectional view depicting the completedconventional combination type thin film magnetic head;

[0121]FIG. 11 is a cross sectional view showing a pole portion of theconventional combination type thin film magnetic head;

[0122]FIG. 12 is a plan view of the convention combination type thinfilm magnetic head;

[0123] FIGS. 13A, 13B-26A, 26B are cross sectional views illustratingsuccessive steps of a first embodiment of the method of manufacturingthe thin film magnetic head according to this invention;

[0124]FIGS. 12A and 27B are cross sectional view depicting the completedthin film magnetic head;

[0125]FIG. 28 is a plan view showing the configuration of the secondmagnetic layer in the first embodiment;

[0126]FIG. 29 is a plan view illustrating a configuration of the secondmagnetic layer, of another embodiment of the thin film magnetic headaccording to this invention;

[0127]FIGS. 30A ad 30B form cross-sectional views showing the trimstructure of the first magnetic layer of another embodiment of the thinfilm magnetic head according to the invention;

[0128]FIG. 31 is a cross sectional view depicting a condition in whichan element separating insulating layer having a thickness of t₁ isformed in the method of manufacturing the thin film magnetic headaccording to the invention;

[0129]FIG. 32 is a cross sectional view showing the completed thin filmmagnetic head;

[0130]FIG. 33 is a cross sectional view depicting, a condition in whichan element separating insulating layer having a thickness of t₂ isformed in the method of manufacturing the thin film magnetic headaccording to the invention;

[0131]FIG. 34 is a cross sectional view showing the completed thin filmmagnetic head;

[0132]FIG. 35A, 35B-38A, 38B are cross sectional views showingsuccessive steps oft a second embodiment of the method of manufacturing,the thin film magnetic head according to the invention;

[0133]FIG. 39 is a plan view illustrating the combination type thin filmmagnetic head in the step of FIG. 38;

[0134] FIGS. 40A, 40B-47A, 47B are cross sectional views showingsucceeding steps of the second embodiment;

[0135]FIG. 48 is a plan view illustrating the composite type thin filmmagnetic head in the step of FIG. 47;

[0136]FIGS. 49A and 49B are cross sectional views depicting a step nextto the step of FIG. 47;

[0137]FIGS. 50A and 50B are cross sectional views showing thecombination type thin film magnetic head in which the insulating layerhas a large thickness; and

[0138] FIGS. 51A, 51B-51A, 59B are cross sectional views illustratingsuccessive, steps of a third embodiment of the method of manufacturingthe combination type thin film magnetic head according to the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0139] FIGS. 13-27 show successive steps of a first embodiment of themethod of manufacturing the thin film magnetic head according to theinvention, and FIGS. 21 and 29 are plan views illustrating the thin filmmagnetic head during the manufacturing process. In FIGS. 13-27, Adenotes a cross sectional view cut along a line perpendicular to the airbearing surface and B denotes a cross sectional view of a pole portioncut along a line parallel with the air bearing surface. The thin filmmagnetic head of the present embodiment a reversed combination type tinfilm magnetic head, in which an inductive type writing thin filmmagnetic head is provided on a substrate and a magnetoresistive typereading thin film magnetic head is arranged on the inductive type thinfilm magnetic head.

[0140] At first as shown in FIG. 13, an insulating layer 22 made ofalumina (Al₂O₃) and having a thickness of about 0.3-0.5 μm is formedsputtering on one surface of a substrate main body 21 made of AlTiC. Itshould be noted that a silicon oxide layer may be used instead of thealumina layer, and the deposition may be carried out by CVD (ChemicalVapor Deposition) instead of sputtering. In this specification, aninsulating layer means a film having at least an electrically insulationproperty and may have or may not have a non-magnetic property. Ingeneral, a material such as alumina having both the electricallyinsulating property and non-magnetic property is used, and therefore theinsulating layer and the non-magnetic layer are sometimes used to havethe same meaning.

[0141] Next as shown in FIG. 14, a photoresist layer 23 is selectivelyformed on the alumina insulating, layer 22 and then as depicted in FIG.15, a metal layer 24 made of a permalloy is formed by plating with athickness of about 5 μm, said metal layer serving as a mask whichdefines an etching profile for at recessed portion to be formed later byperforming the etching for the substrate 21. This metal layer 24 may bemade of other metal or metal compound such as copper, nickel, nickelboron instead of permalloy. Since the metal layer 24 is used as a maskfor the formation of the recessed portion in the substrate, thepermalloy may have any desired composition.

[0142] Next, as illustrated in FIG. 16, the etching is carried out usingthe metal layer 24 as a mask to form a recessed portion 25 having agiven profile in a surface of the substrate 21. In the presentembodiment, this etching is of a reactive ion etching which is one ofdry etchings, but ion beam milling such as ion milling, wet etching andso on may be used. According to the invention, parameters of the thinfilm magnetic head such as throat height MR height and apex angle θ aredetermined by a profile of the recessed portion 25, and therefore thedry etching is preferably used owing to a fact that a depth and aconfiguration of a side wall can be controlled precisely with an orderof 0.1 μm and the recessed portion can be formed at a higher speed. As agas used in the dry etching, a fluorine series gas such as CF₄ and SF₆,a chlorine series gas such as BCl₃ and Cl₂ or one of these gases dilutedwith O₂ or inert gas such as N₂, Ar and He.

[0143] In the present embodiment, since the apex angle θ is determinedby an inclination angle of the side wall of said recessed portion 25, itis preferable to form the recessed portion such that the side wall ofthe recessed portion has the inclination angle of 45-70°, particularly55-65° in accordance with the desired apex angle.

[0144] When the recessed portion 25 is formed by the dry etching asstated above, although the smoothness of the inner wall of the recessedportion is superior to that formed by other processes, there are formedsharp protrusions and depressions of about 0.1-0.5 μm. If suchprotrusions and depressions might cause undesired degradation in theinsulating property of first magnetic layer and thin film coil of thethin film magnetic head to be formed within the recessed portion 25, theprotrusions and depressions may be removed by the argon sputtering.After forming the recessed portion in this manner, the metal layer 24serving as the mask is removed as illustrated in FIG. 17. It should benoted that according, to the invention, such sputtering is not alwaysrequired and it is not necessary to remove the metal layer 24.

[0145] Next, as shown in FIG. 18, an alumina insulating layer 26 havinga thickness of 0.3-5.0 μm is formed by sputtering, said insulating layerserving to separate the thin film magnetic head element from thesubstrate 21. It should be noted that in the present embodiment, thealumina insulating layer 22 serving as a buffer layer is remained, butit may be removed together with the plated material layer. In this case,the alumina insulating layer 22 becomes integral with the aluminainsulating layer 26, and therefore in FIG. 18, the alumina insulatinglayer 22 is not shown. Furthermore, a thick alumina insulating layer 22may be remiained and may be utilized as a part of a member for definingthe recessed portion 25.

[0146] Next, in order to form one of poles, a mask made of a photoresistis formed on the surface of the first magnetic layer 24 in accordancewith a predetermined pattern as shown in FIG. 15, and the first magneticlayer 24 is selectively etched. During this etching process, the firstmagnetic layer 24 formed on the island-like insulating layer 22 isremoved.

[0147] Although in this embodiment, the one of shields is formed byetching the first magnetic layer 24 used as the mask for forming therecessed portion 25 into a desired pattern, the mask for forming therecessed portion may be made of a metal or metal compound and the firstmagnetic layer may be formed in accordance with a predetermined patternafter removing the mask.

[0148] Subsequently as shown in FIG. 16, an insulating layer 26 made ofalumina is formed, with a thickness of 0.3-0.5 μm, on the inner surfaceof the recessed portion 25 and on the first magnetic layer 24, then asecond magnetic layer 7 constituting a part of one of poles and having,a thickness of about 4 μm is formed in accordance with a given patternon the insulating layer 26, and thereafter an insulating layer 28 madeof alumina is formed with a thickness of 0.5-1 μm on said secondmagnetic layer.

[0149]FIG. 17 is a plane view showing the second magnetic layer 27formed in accordance with the predetermined pattern as mentioned above.In FIG. 17, the insulating layer 28 formed on the second magnetic layer27 is omitted and a thin film coil and a pair of poles for an inductivetype thin film magnetic head to be formed later are denoted by imaginarylines.

[0150] As explained above, the recessed portion 25 is formed in thesurface of the substrate 21 such that the apex angle is defined by theside wall of the recessed portion, and therefore the apex angle is notchanged by the heating treatment of 250° C. during the formation of thethin film coil. The inclination angle of the side wall of the recessedportion 25 can be formed at will by suitably selecting the usually usedetching conditions, materials of the mask and buffer layer, butaccording to the invention, the inclination angle may he preferably setto 45°-75°, particularly 55°-65°. In the present embodiment, saidinclination angle is set to 60°.

[0151] Moreover, a photoresist layer or SOG (Spin On Glass) layer may beformed on the above mentioned element separating alumina insulatinglayer 26 to obtain a recessed portion 25 having a smooth surface byembedding the sharp protrusions and depressions within the photoresistlayer or SOG layer.

[0152] Then, as depicted in FIG. 19, a first magnetic layer 27constituting one of poles of the thin film magnetic head is formed witha thickness of 3-4 μm. In the present embodiment, this first magneticlayer 27 is made of a permalloy (Ni:80 wt %, Fe:20 wt %), but it may bemade of a magnetic material having a high cohesive force such as ironnitride or amorphous magnetic material such as Fe—Co—Zr. Furthermore, inthe present embodiment, the first magnetic layer having a given patternis formed by the plating which uses a pattern layer obtained by thephotoresist technique, but according to the invention, after forming apermalloy layer by the sputtering, the first magnetic layer may beformed by the dry etching such as the ion milling using a photoresistpattern and an alumina mask.

[0153] Further, as shown in FIG. 20, a thin film coil 29 is formedwithin the recessed portion 25 such that the thin film coil iselectrically insulated by an insulating layer 28. In the presentembodiment, this insulating layer 29 is made of a photoresist, but maybe made of SOG layer which has been generally used in the flatteningprocess in the semiconductor device manufacturing method or a siliconoxide or silicon nitride formed by the plasma CVD. In any case, in orderto flatten the surface of the insulating layer 28, the heating treatmentat about 250° C. is conducted, but in the present embodiment, aconfiguration of the recessed portion 25 is not changed by such aheating treatment.

[0154] Next as shown in FIG. 21, an alumina insulating layer 30 isformed on an exposed surface of the first magnetic layer 27 as well ason a surface of the insulating layer 28 with a thickness of 4-5 μm. Theinsulating layer 30 may be made of silicon oxide or silicon nitrideinstead of alumina. Next, the alumina insulating layer 30 is flattenedby the chemical mechanical polishing (CMP) as depicted in FIG. 22. Thispolishing treatment is carried out until the surface of the firstmagnetic layer 27 is exposed.

[0155] Then, as illustrated in FIG. 23, on a gap layer 31, a secondmagnetic layer 32 (referred to pole chip) is selectively formed inaccordance with a given pattern with a thickness of about 1-4 μm, saidsecond magnetic layer defining a width W of record tracks. The secondmagnetic layer 32 is made of a permalloy (Ni:50 wt %, Fe:50 wt %). Afterthat, a portion of the gap layer 31 near the pole chip 32 is selectivelyremoved by performing the reactive ion etching or ion beam etching,while the pole chip is used as a mask. Then, the exposed first magneticlayer 27 is etching over a depth of 100-200 nm by, for instance the ionmilling to form a trim structure as shown in FIG. 24.

[0156] It should be noted that in the specification, the pole portionmeans a region extending from the edge of the recessed portion 25 to theend surface of the stacked body, over which the first magnetic layer 27,gap layer 31 and second magnetic layer (pole chip) 32 are contacted witheach other. Therefore, in a final process, when the end surface ispolished to form the air bearing surfaces the pole portion isconstructed by a region extending from the edge of the recessed portion25 to the air bearing, surface, and this distance corresponds to thethroat height TH.

[0157] In the present embodiment, it is important that the secondmagnetic layer 32 is formed not only over the pole portion, but alsoover a rear region beyond the pole portion. In the known thin filmmagnetic head, the pole chip and top pole are contacted with each otherover a small area and they are brought into contact with each other atright angles, and therefore the magnetic flux is liable to be saturatedat this contact area and a sufficiently satisfactory writing performancecan not be attained. However, in the present embodiment, the pole chipand top pole are brought into contact with each other not only at thepole portion, but also at the rear portion beyond the pole portion, andtherefore the above mentioned saturation of the magnetic flux can beeffectively avoided. As a result of this, a sufficiently satisfactorywriting performance (an be obtained. It should be noted that if therecan be obtained a sufficiently large contact area, the pole chip and toppole may be contacted with each other only at the rear portion beyondthe pole portion.

[0158] According to the invention, there is no limitation in a shape ofthe rear portion of the pole chip 32 beyond the pole portion, and may beshaped to extend straightly as illustrated in FIG. 28 or may be shapedto widen toward the rear as depicted in FIG. 29 as long as the pole chipand third magnetic layer are brought into contact with each other at therear region beyond the pole portion. Furthermore, in FIG. 29, the rearportion of the pole chip beyond the pole portion is widened at anexpansion angle of about 90°, but the expansion angle is not limited tothis value but may be set any value within a range of 30-180°. Apreferable angle range is 45-120°. It should be noted that in FIGS. 28and 29, a third magnetic layer 34 to be formed later is denoted by animaginary line.

[0159] After forming the second magnetic layer 32 in the mannerexplained above, an alumina insulating layer 33 having a thickness of3-4 μm is formed, and then the second magnetic layer 32 is exposed byCMP and a third magnetic layer 34 made of a permalloy like as the firstmagnetic layer 27 is formed with a thickness of 3-4 μm as shown in FIGS.25. As explained above with reference to FIGS. 27 and 28, the thirdmagnetic layer 34 has a plan configuration which is substantially equalto a regular pentagon with a pole portion. In this manner, the thirdmagnetic layer 34 is formed such that it expands toward the backward andcovers the second magnetic layer 32. Therefore, although an alignment ofthe third magnetic layer with respect to the pole chip deviatesslightly, the contact area as a whole is not changed, and the saturationof the magnetic flux can be avoided.

[0160] It should be noted that the third magnetic layer 34 is broughtinto contact with the first magnetic layer 27 via the second magneticlayer 32 at a rear portion remote from the pole portion, and thereforethe thin film coil 29 passes through a closed magnetic path formed bythe first, second and third magnetic layers.

[0161] Next, as illustrated in FIG. 26, a MR layer 36 for constitutingthe MR element is formed on the third magnetic layer 34 such that the MRlayer is embedded within a non-magnetic and electrically insulatingshield gap layer 35, and then a magnetic shield layer 37 for the MRelement is formed with a thickness of 3-4 μm and an overcoat layer 38made of alumina is formed for protecting the MR element.

[0162] Finally, as shown in FIG. 28, the side surface at which the gaplayer 31 and MR layer 36 are formed is polished to form the air bearingsurface 39 which is to be opposed to a magnetic record medium and an MRelement 40 having a desired MR height. In the present embodiment, theedge of the recessed portion 25 formed in the substrate 21 is used asthe positional reference for the air bearing surface 39. Since aposition of this edge is not varied during the manufacturing process, itis possible to define the throat height TH, MR height MRH and apex angleθ which are accurately correspond to desired design values.

[0163] The above mentioned second magnetic layer 32, i.e. pole chip maybe made of a material halving a high saturation magnetic flux densitysuch as iron nitride (FeN), Fe—Cr—Zr series amorphous alloy and Fe—Cseries amorphous alloy in addition to the above stated permalloy (Ni:50wt %, Fe:50 wt %). Moreover, more than one of these materials may beused by stacking.

[0164] Moreover, the first and second magnetic layers 27 and 34 may bemade of any kinds of known materials having a high saturation fluxdensity in addition to the above mentioned permalloy (Ni:80 wt %, Fe:20wt %).

[0165] Further, the gap layer 31 may be made of an oxide such as Al₂O₃and SiO₂, a nitride such as AlN, BN and SiN or an electricallyconductive non-magnetic material such as Au, Cu and NiP.

[0166]FIGS. 30A and 30B show another embodiment of the combination typethin film magnetic head manufactured by the method according to theinvention. In the above explained embodiment, as shown in FIG. 24, uponforming the trim structure by etching the gap layer 31 and firstmagnetic layer 27 while the pole chip 32 of the pole portion is used asa mask. In the present embodiment, the first magnetic layer 27 is etchedover its whole thickness while the pole chip 32 is used as a mask. Incase of etching the first magnetic layer 27 over a part of its thicknessin the previous embodiment, the magnetic flux might leak at the edge atwhich the first magnetic layer does not overlap with the pole chip 32,and thus a track width might be widened due to the writing by the leakedmagnetic flux. However, in the present embodiment, since the etching isperformed over a whole thickness of the first magnetic layer 27, thereis not formed such an edge at which the first magnetic layer does notoverlap with the pole chip 32, and the above undesired widening of theeffective track width cain be avoided.

[0167]FIGS. 31 and 32 show an embodiment in which the elementseparating, insulating layer 26 is formed to have a thickness t₁, andFIGS. 33 and 34 illustrate another embodiment in which the elementisolating insulating layer 26 has a thickness of t₂ which is larger thanthe thickness t₁. When the element isolating insulating layer 26 havedifferent thicknesses, a distance d₁ from the edge of the recessedportion 25 formed in the substrate 21 to an edge of the MR reproducingelement 40 opposite to an edge which exposes on the air bearing surface39 is identical in both embodiments, but a distance from the edge of therecessed portion to the rear edge of the pole portion of the firstmagnetic layer 27 becomes d₂ in the embodiment shown in FIGS. 31 and 32and becomes d₃ in the embodiment depicted in FIGS. 33 and 34, d₃ beinglonger than d₂. In this manner, the distance d₂, d₃ from the edge of therecessed portion 25 to the rear edge of the first magnetic layer 27 canbe controlled, while the distance d₁ from the edge of the recessedportion to the rear edge of the MR reproducing element 40 is remainedunchanged.

[0168] In this manner, according to the invention, the balance betweenthe throat height TH and the MR height MRH can be adjusted bycontrolling a thickness of the element isolating insulating layer 26,and therefore a manufacturing, yield of the combination type thin filmmagnetic head can be improved. Furthermore, during the manufacturingprocess, it is very easy to control a thickness of the element isolatinginsulating layer 26, and thus various requests of users can be respondedeasily and promptly.

[0169] FIGS. 35-49 show successive steps of a second embodiment of themethod of manufacturing the combination type thin film magnetic headaccording to the invention. Also in these drawings, A denotes a crosssectional view cut along a line perpendicular to the air bearingsurface, and B represents a cross sectional view of the pole portion cutalong a line parallel with the air bearing surface.

[0170] At first, as shown in FIG. 35, an insulating layer 122 made ofalumina and having a thickness of about 10 μm is formed on one surfaceof a substrate main body 121 made of AlTiC. In the presentspecification, a combination of these substrate main body 121 andinsulating layer 122 is called a substrate or wager 123. Further, inthis specification, an insulating layer means at film having at least anelectrically insulation property and may have or may not have anon-magnetic property. In general, a material such as alumina havingboth the electrically insulating property and non-magnetic property isused, and therefore the insulating layer and the non-magnetic layer aresometimes used to have the same meaning.

[0171] Next, as shown in FIG. 36, a first magnetic layer 124 is formedon the insulating layer 122 of the substrate 123 such that the firstmagnetic layer includes an opening at a portion at which a recessedportion is to be formed later, said first magnetic layer constitutingone of the shields for the magnetoresistive type thin film magnetichead. Then, the reactive icon etching is performed using the firstmagnetic layer 124 as a mask to form a recessed portion 125 in thesurface of the insulating layer 122 as shown in FIG. 36. In this figure,a periphery of the opening of the first magnetic layer 124 defining therecessed portion 125 is denoted as a reference numeral 124 a. Asillustrated in FIG. 36, at a central portion of the recessed portion 125there is remained a part of the insulating layer 122 like as an islandand the in magnetic layer is formed on its top surface. This structureis required for coupling the other pole to be formed later with the onepole.

[0172] In the present embodiment the first magnetic layer 124 is made ofa permalloy and is formed by the plating. The reactive ion etching canbe conducted using the gas such as BCl₃, Cl₂, CF₄, SF₆. By such areactive ion etching, it is possible to form the recessed portion 125having a large depth of not less than 5 μm in an accurate manner. In thepresent embodiment, the recessed portion 125 has a depth of 7-8 μm.

[0173] In the present embodiment, the apex angle θ is determined by aninclination angle of the side wall of said recessed portion 25, and theside wall of the recessed portion has the inclination angle of 45-70°,particularly 55-65°. In the present embodiment, the inclination angle isset to about 60°.

[0174] In order to form one of the poles, a mask made of a photoresistis formed on the first magnetic layer 124 in accordance with a givenpattern, and then the first magnetic layer is selectively etched asdepicted in FIG. 37. During this etching process, the first magneticlayer 124 formed on the island-shaped insulating layer 122 is removed.

[0175] In the present embodiment, one of the shields is formed byetching the first magnetic layer 1 24 which has been used as the maskfor forming the recessed portion 125 after the formation of the recessedportion 15. According to the invention, a task for forming the recessedportion may be made of metal or metal compound, and the first magneticlayer may be formed in accordance with a given pattern after removingthe mask.

[0176] Next, as shown in FIG. 38, an alumina insulating layer 126 havinga thickness of 0.2-0.8 μm is formed on the inner surface of the recessedportion 125 as well as on the first magnetic layer 124 in accordancewith a given pattern, a second magnetic layer 127 constituting the otherpole is formed thereon with a thickness of about 4 μm in accordance witha given pattern and then an alumina insulating layer 128 having athickness of 0.5-1 μm is formed thereon. As explained above, accordingto the present invention, by controlling a thickness of the insulatinglayer 128 within a range of 0.2-0.8 μm, the throat height can becontrolled without changing the MR height.

[0177]FIG. 37 is a plan view showing the condition after the secondmagnetic layer 127 is formed in accordance with a given pattern. In FIG.39, the insulating layer 128 formed on the second magnetic layer 127 isdispensed with and the thin film coil and poles of the inductive typethin film magnetic head to be formed later are denoted by imaginarylines.

[0178] In the actual manufacturing process, after forming a number ofcombination type thin film magnetic heads in a matrix on the wafer, thewafer is divided into bars, a side edge of respective bars is polishedto form the air bearing surfaces, and finally the bar is divided into aplurality of the combination type thin film magnetic heads. However, inthe drawings, only a single thin film magnetic head is shown.

[0179] Subsequently as shown in FIG. 40, a two layer thin film coil 130is formed within the recessed portion 25 such that the thin film coil iselectrically insulated by an insulating layer 129, within said recessedportion having been formed the insulating layer 126 having a controlledthickness, second magnetic layer 127 and insulating layer 128. Duringthe formation of this thin film coil 130, the annealing process iscarried out at a temperature of 200-250° C. to flatten the surface.

[0180] Next, is shown in FIG. 41, an alumina insulating layer 131 isformed on a whole surface with a thickness of 3-4 μm. This insulatinglayer 130 may be made of silicon oxide instead of alumina.

[0181] Then, the alumina insulating layer 131 is flattened by thechemical mechanical polishing (CMP) Such that the surface of the firstmagnetic layer 124 is exposed, and the surface of the first insulatinglayer 124 is brought into co-planer with the surface of the firstmagnetic layer as depicted in FIG. 42. By performing such a process, athickness of the first magnetic layer 124 which are about 4 μm in anoriginal condition is reduced to about 3 μm. Furthermore, in thiscondition, the edge of the second magnetic layer 127 is exposed.

[0182] In the present embodiment, the assembly shown in FIG. 42 iscalled a common unit for thin film magnetic head which can be commonlyused for manufacturing combination type thin film magnetic heads havingvarious properties. A number of common units for thin film magneticheads are previously manufactured and stocked, and a combination typethin film magnetic head having a property required by a user can bemanufactured while the common unit is utilized as a starting material.In this manner, according to the invention, various requests of userscan be suitably and promptly satisfied by the above feature togetherwith the above mentioned feature that the throat height can becontrolled easily without loosing a balance between the throat heightand the MR height.

[0183] Next, as illustrated in FIG. 43, a shield gap layer 133 having aMR layer 132 embedded therein is formed on the first magnetic layer 124.This can be performed be performed in the following manner. Afterforming an alumina layer having thickness of about 0.1 μm, the MR layer132 constituting the AMR element or GMR element in accordance with agiven pattern, a lead pattern (not shown) for the MR layer is formed,and finally an alumina layer is formed with a thickness of 0.1 μm. Forthe sake of clarity, in FIG. 43, these alumina layers ire shown as asingle united shield gap layer 133. Furthermore, the MR layer 132 istrimmed on the first magnetic layer 124 only at a region at which thepole portion will be formed later, but the shield gap layer 133 isformed on a whole surface.

[0184] Next parts of the shield gap layer 127 formed on the edge and theisland-like portion of the second magnetic layer 127 are selectivelyremoved. This process may be conducted by the lift-off process, but inthe present embodiment, the process is carried out by selectivelyremoving the alumina of the shield gap layer 133 by means of thereactive ion etching with BCl₂ series gas, while the photolithography isutilized.

[0185] Then, as shown in FIG. 44, a third magnetic layer 134 is formedsuch that the third magnetic layer is coupled with the second magneticlayer 127 at the edge of the recessed portion 125. In the presentembodiment, the third magnetic layer 134 is formed by depositing apermalloy by the plating with a thickness of about 3.5 μm. Then, analumina insulating layer 135 is formed on a whole surface with athickness of several microns, and is flattened by CMP to expose thethird magnetic layer 134 as depicted in FIG. 45. Also in this process,the over-etching is conducted such that a part of the third magneticlayer 134 is exposed, and therefore a thickness of the third magneticlayer is reduced to about 3 μm and the third magnetic layer formed onthe island-like portion is also exposed.

[0186] After that, a write gap layer 136 made of alumina is formed on awhole surface with i thickness of 150-200 nm, a part of the write gaplayer situating on the island-like portion is selectively removed, andthen a fourth magnetic layer 137 constituting the other pole is formedin accordance with a given pattern with a thickness of about 3 μm asillustrated in FIG. 46. This fourth magnetic layer 137 has a narrow poleportion. Further, the fourth magnetic layer 137 is brought into contactwith the third magnetic layer 134 formed on the above mentionedisland-like portion, and said third magnetic layer is coupled with thesecond magnetic layer. In this manner, there is formed a closed magneticcircuit which surrounds a part of the thin film coil 130.

[0187] Next, the reactive ion etching is performed using the poleportion of the fourth magnetic layer 137 as a mask, and a portion of thewrite gap layer 136 in a vicinity of the pole portion is selectivelyremoved as depicted in FIGS. 47 and 48. By removing the write gap layer136 by the reactive ion etching, the etching can be done within a shorttime period, and thus a reduction in a thickness of the fourth magneticlayer 137 is small. For the sake of simplicity, in FIG. 48, the thinfilm coil 130 and third magnetic layer 134 underneath the write gaplayer 136 are denoted by solid lines.

[0188] Next, the surface of the third magnetic layer 134 is partiallyremoved by the ion beam etching, in the present embodiment by the ionmilling while the pole portion of the write gap layer 136 is used as amask to form the trim structure as shown in FIG. 49. By forming the trimstructure in the surface of the third magnetic layer 134 using the poleportion of the fourth magnetic layer 137 and write Yap layer 136, thetrim structure can be always aligned with respect to the other poleconstituted by the fourth magnetic layer, and thus the leakage of themagnetic flux can be effectively suppressed.

[0189] Moreover, when the ion beam etching is used for etching the thirdmagnetic layer 134 and the etching angle is suitably selected, a sideconfiguration of the trim structure can be improved.

[0190] Furthermore, a protecting overcoat layer 139 made of alumina isformed on a whole surface with a thickness of 3-5 μm, and then theetching is carried out to expose contact pads connected to the thin filmcoil 130 of the inductive type thin film magnetic head and contacts padsconnected to) the MR layer 132 of the magnetoresistive type thin filmmagnetic head. In the present embodiment, since the fourth magneticlayer 137 has a flat surface and the overcoat layer 139 can be thin, theabove etching such as ion milling and reactive ion etching for exposingthe contact pads can be easily performed within a short time period. Inthe conventional combination type thin film magnetic head, it isnecessary to provide the thick overcoat layer, the etching for exposingthe contact pads requires a long time period. Therefore, the throughputis decreased.

[0191] After the respective components of the combination type thin filmmagnetic head have been formed on the wafer 123, the wager is dividedinto a plurality of bars, in each of which a number of combination typethin film magnetic heads are aligned. Then a side edge of a bar ispolished to form the air bearing surface, and finally the bar is dividedinto respective combination type thin film magnetic heads. During thepolishing process for the air bearing surface, the position of the edgeof the recessed portion 125 is used as a positional reference and sincethis position is not deviated during the manufacturing process, it ispossible to obtain the MR reproducing element having a desired MR heightcorresponding to a design value.

[0192] As shown in FIGS. 49 and 50, also in the present embodiment, bychanging a thickness of the element isolating insulating layer 126, thethroat height can be controlled without changing the MR height. Itshould be noted that in the embodiment shown in FIG. 50, a thickness ofthe element isolating insulating layer 126 is larger than that of theembodiment illustrated in FIG. 49, and thus the throat height in FIG. 50is longer than that in FIG. 49. However, the MR height is identical inboth embodiments. It should be noted that FIGS. 49 and 50 depict thecondition prior to the polishing for the air bearing surface, and thusactual throat height and MR height become smaller, but the aboveexplained relation is not changed at all.

[0193] In FIG. 49, a thickness of the element isolating insulating layer126 is denoted by t₁ and a thickness of this layer is represented by t₂which is larger than t₁. By changing a thickness of the elementisolating, insulating layer 126 in this manner, although, a distance d₁from the edge of the recessed portion 125 formed in the substrate 123 tothe edge of the MR layer 132 opposite to the air bearing surface, adistance from the edge of the recessed portion to the rear edge of thepole portion of the second magnetic layer 127 becomes d, in FIG. 49 andbecomes d₃ which is longer than d, in FIG. 50. That is to say, also inthis embodiment, a distance d₂, d₃ from the edge of the recessed portion125 to the rear edge of the second magnetic layer 127 can be controlled,while a distance d₁ from the edge of the recessed portion to the rearedge of the MR reproducing element 132 is remained constant.

[0194] In the present invention, since the balance between the throatheight TH and the MR height can be adjusted by controlling a thicknessof the element isolating, insulating layer 126, the yield ofmanufacturing, the combination type thin film magnetic head can beimproved. Further, during the manufacturing process, a thickness of theelement isolating insulating layer 126 can be controlled simply, variousrequirements of users can be satisfied in an easy and prompt manner.

[0195] In the present embodiment, during the polishing for obtaining theair bearing surface the edge of the recessed portion 125 is used as apositional reference, and since this position is not changed during themanufacturing process the throat height TH and MR height MRH can beformed to have desired design values. Moreover, the apex angle θ isdetermined by the inclination angle of the side wall of the recessedportion 125 and this inclination angle can be accurately set to adesired angle and is not changed during the manufacturing process.Therefore, it is possible to obtain the combination type thin filmmagnetic head having a desired apex angle θ. In this manner, in thecombination type thin film magnetic head according to the invention, asufficient miniaturization can be attained without degrading theperformance.

[0196] Furthermore, although the combination type thin film magnetichead is of the normal type in which the inductive type thin film writingmagnetic head is stacked on the MR reproducing element, since the MRelement 132 is formed after the heating treatment at about 250° C. forforming the thin film coil 130, the MR layer is not affected by theheating treatment and a MR layer having a higher sensitivity but beingliable to be influenced by heat may be advantageously used.

[0197] FIGS. 51-58 show a third embodiment of the method ofmanufacturing the combination type thin film magnetic head according tothe invention. Also in these drawings, A denotes a cross sectional viewcut along a line perpendicular to the air bearing surface and B shows across sectional view of the pole portion cut along a line parallel withthe air bearing surface. In the present embodiment, the combination typethin film magnetic head having the normal configuration, in which the MRreproducing element is formed on the substrate and the inductive typethin film writing magnetic head is stickled on the MR element.

[0198] At first, as shown in FIG. 51, a substrate 223 is prepared byforming an alumina insulating layer 222 on a substrate main body 221made of AlTiC, and then a first magnetic layer 224 is formed thereon inaccordance with a given pattern. Next, as illustrated in FIG. 52, thereactive ion etching, is performed using the first magnetic layer as amask to form a recessed portion 225. An island-like portion is remainedat a center of the recessed portion 225.

[0199] Next, as depicted in FIG. 53, after selectively removing thefirst magnetic layer 224 on the island-like portion within the recessedportion 225, a first insulating layer 226 having a controlled thicknessis formed on an inner surface of the recessed portion 225. Further, asshown in FIG. 54, a MR layer 228 is formed on the first insulating layer224 in accordance with a given pattern such that the MR layer isembedded within a shield gap layer 227.

[0200] Next, as shown in FIG. 55, a second magnetic layer 229 is formedon the first insulating layer 226 within the recessed portion 225 aswell as on the shield gap layer 227. Then, as shown in FIG. 56, a thinfilm coil 30 is formed within the recessed portion 225 such that thethin film coil is supported by a second insulating layer 231 in anelectrically isolated manner. Next, as depicted in FIG. 57, afterforming a third insulating layer 232 on the second magnetic layer 229and second insulating layer 231 the etch-back is carried out to exposethe surface of the second magnetic layer 229 and to form a flat surface.

[0201] Next, as shown in FIG. 58, a gap layer 233 is formed. An opening234 is formed in a rear portion of this gap layer 233 through the secondand third insulating layers 231 and 232 to exposed the surface of thesecond magnetic layer 229.

[0202] Then, as depicted in FIG. 59, a third magnetic layer 235 isformed on the gap layer 233. This third magnetic layer 235 is coupledwith said second magnetic layer 229 through said opening 234.

[0203] Following steps are identical with those of the above explainedembodiment, and their detailed explanation is dispensed with. Also inthe present embodiment, by controlling ;a thickness of the firstinsulating layer 226 formed on the inner wall of the recessed portion225, the reference position of throat height zero can be changed, andtherefore the throat height can be controlled. However, the MR heightMRH is not changed even if a thickness of the first insulating layer 226is changed. In this manner, the throat height TH can be controlled in asimple and accurate manner without breaking, a balance between thethroat height TH and the MR height MRh.

[0204] The present invention is not limited to the above embodiments andmany alternations and modifications may be conceived within the scope ofthe invention. For example, in the above embodiments, the MR reproducingelement is constructed by the AMR element, but according to theinvention, the MR reproducing element may be formed by the GMR elementusing spin bulb layer, super-lattice GMR layer and granular GMR layer.These GMR elements have a drawback that the reproduced output isdeceased to a large extent by the high temperature annealing at about250° C. for forming the thin film coil of the thin film magnetic head.For instance, in the spin bulb film having Ni—Fe magnetic and Cunon-magnetic layers, a multi-layer structure of the spin bulb film mightbe destroyed by heating at a temperature not lower than 250° C. due to amixing of Ni and Cu. In the above mentioned first and second embodimentsaccording to the invention, the formation of the thin film coil withinthe recessed portion has been completed before forming the GMR film, andthus the GMR film is not affected any more.

[0205] Moreover, in the above mentioned first embodiment, the trimstructure is formed in the first magnetic layer 27 by conducting theetching process using the pole chip 32 formed by the second magneticlayer as a mask, but such a trim structure is not always necessary.

[0206] Moreover in the above embodiments, the thin film magnetic head isconstructed as the combination type thin film magnetic head in which therecording thin film magnetic head and MR reproducing element are stackedbut according to the invention it is not always necessary are stacked,but according to the invention it is not always type thin film magnetichead may be formed.

[0207] As explained above, according to the thin film magnetic head, thefirst insulating layer and thin film coil are formed within the recessedportion formed in the surface of the substrate, the second magneticlayer constituting the pole chip is formed via the gap layer, and thethird magnetic layer is formed to be contacted with the second magneticlayer. Therefore, the throat height TH and apex angle 0 can be formedaccurately to have desired design values and the performance of the thinfilm magnetic head can be improved. Furthermore, in the combination typethin film magnetic head having the reproducing head constructed by themagnetoresistive element, the formation of the thin film coil has beenfinished prior to the formation of the magnetoresistive element, andthus the magnetoresistive element is not affected by the heatingtreatment for forming the thin film coil and the GMR element having ahigh sensitivity can be utilized, said GMR element being affected by theheating treatment.

[0208] According to the invention, when the trim structure is formed byetching the first magnetic layer using the pole chip constructed by thesecond magnetic layer as a mask, the magnetic flux is not expandedduring the writing and thus the effective track width is not expanded.Therefore the track width of sub-microns can be realized and the surfacerecording density can be materially improved. Further, the trimstructure is formed by using the pole chip as a mask, the trim structurecan be formed accurately by the self-alignment.

[0209] Furthermore, the second magnetic layer is extended inwardlybeyond the pole portion, and thus a sufficiently large contact area canbe attained between the second magnetic layer and the third magneticlayer, and the writing magnetic flux is not saturated at a point beforethe pole portion.

[0210] In the method of manufacturing the combination type thin filmmagnetic head according to the invention, by controlling a thickness ofthe insulating layer formed on the inner surface of the recessed portionformed in the substrate, the throat height zero reference position forthe throat height of the inductive type thin film writing magnetic headcan be controlled. In this case, the MR height of the MR reproducingelement is not influenced at all, and therefore the throat height can beformed to have a desired design value without destroying the balancedcondition between the throat height and the MR height.

[0211] Moreover, the control of a thickness of the insulating layer canbe performed very easily without changing largely the manufacturingprocess and therefore various requirements of users can be satisfied inin easy and prompt manner.

[0212] Furthermore, the apex angle of the inductive type thin filmwriting magnetic head is determined by the inclination angle of the sidewall of the recessed portion and this inclination angle is not changedduring the manufacturing process. Therefore, it is possible tomanufacture the combination type thin film magnetic head having the apexangle corresponding to the desired design value.

1. A thin film magnetic head comprising: a first magnetic layer having apole portion; a second magnetic layer having a pole portion which is tobe opposed to a magnetic record medium and defines a width of recordtracks, and end surface of said pole portion constituting an air bearingsurface together with an end surface of said pole portion of said firstmagnetic layer; a third magnetic layer which is brought into contactwith said second magnetic layer on a side opposite to said firstmagnetic layer and is magnetically coupled with said first magneticlayer at a portion remote from said air bearing surface; a gap latermade of a non-magnetic material and being interposed between the poleportion of the first magnetic layer and the pole portion of the secondmagnetic layer at least at the air bearing surface; a thin film coilhaving a portion which is arranged between said first magnetic layer andsaid second and third magnetic layers by means of an insulating layer togenerate a writing magnetic flux for the magnetic record medium; and asubstrate which supports said first, second and third magnetic layers,gap layer, insulating layer and thin film coil; wherein said secondmagnetic layer is extended up to a rear region beyond said pole portionand an extended portion of the second magnetic layer is brought intocontact with the third magnetic layer, and a part of said first magneticlayer except for at least said pole portion and the thin film coilisolated by said insulating layer are embedded within a recessed portionformed in the substrate.
 2. A thin film magnetic head as claimed inclaim 1, wherein the surface of said insulating layer electricallyisolating said thin film coil and an interface between said second andthird magnetic layers are formed to be coplanar.
 3. A thin film magnetichead as claimed in claim 1, wherein said recessed portion formed in thesubstrate has a side wall which is inclined by 45°-75°.
 4. A thin filmmagnetic head as claimed in claim 3, wherein said side wall of therecessed portion formed in the substrate is inclined by 55°-65°.
 5. Athin film magnetic head as claimed in claim 1, wherein said recessedportion has a depth not less than 5 μm.
 6. A thin film magnetic head asclaimed in claim 1, wherein said second magnetic layer is made of amaterial having a high saturation magnetic flux density.
 7. A thin filmmagnetic head as claimed in claim 1, wherein a portion of said poleportion of the first magnetic layer opposed to the pole portion of thesecond magnetic layer via said gap layer has a trim structure having aheight which is equal to a whole or a part of a thickness of the firstmagnetic layer, and has a width which is substantially equal to a widthof the pole portion of said second magnetic layer.
 8. A thin filmmagnetic head as claimed in claim 7, wherein said trim structure isformed by etching using the a side wall which is inclined by 45°-75°. 9.A thin film magnetic head as claimed in claim 1, wherein a width of therear portion of the second magnetic layer beyond the pole portion iswidened than a width of the pole portion.
 10. A thin film magnetic headas claimed in claim 9, wherein a width of the rear portion of the secondmagnetic layer beyond the pole portion is gradually increased.
 11. Athin film magnetic head as claimed in claim 10, wherein the rear portionof the second magnetic layer beyond the pole portion is widened by anangle of 30-180°.
 12. A thin film magnetic head as claimed in any one ofclaims 1-11, wherein the thin film magnetic head is constructed as acombination type thin film magnetic head by arranging a magnetoresistivetype reproducing element for reading on a surface of the third magneticlayer opposite to the surface which is brought into contact with saidsecond magnetic layer such that an end surface of the reproducingelement is exposed on the air bearing surface.
 13. A method ofmanufacturing a thin film magnetic comprising: the step of forming arecessed portion in a surface of a substrate; the step of forming afirst insulating layer on the surface of the substrate including asurface of the recessed portion; the step of forming a first magneticlayer on a surface of said first insulating layer; the step of forming athin film coil within the recessed portion such that the thin film coilis isolated by a second insulating layer; the step of forming a gaplayer on at least said pole portion of the first magnetic layer as wellas on a surface of said second insulating layer after making said firstmagnetic layer and second insulating layer to have a coplanar surface;the step of forming a second magnetic layer on said gap layer such thatthe second magnetic layer includes a pole portion which extends alongsaid pole portion of the first magnetic layer and a rear portion whichextents beyond the pole portion; the step of forming a third magneticlayer such that the second magnetic layer is brought into contact withthe second magnetic layer and is brought into contact with said firstmagnetic layer at a rear portion remote from the air bearing surface;and the step of forming the air bearing surface to be opposed to amagnetic record medium by polishing said substrate, pole portions ofsaid first and second magnetic layers and gap layer sandwiched by thesepole portions while an edge of the recessed portion formed in thesubstrate is used as a positional reference.
 14. A methodic ofmanufacturing a thin film magnetic head as claimed in claim 13, whereinupon forming said second magnetic layer, a width of said rear portionthereof beyond the pole portion is wider than a width of the poleportion.
 15. A method of manufacturing a thin film magnetic head asclaimed in claim 14, wherein a width of said rear portion of the secondmagnetic ayer is gradually increased.
 16. A method of manufacturing athin film magnetic head as claimed in claim 15, wherein said rearportion of the second magnetic layer is widened at an angle of 30-180°.17. A method of manufacturing a thin film magnetic head as claimed inclaim 13, wherein after forming said second magnetic layer, the poleportion of said first magnetic layer is etched while the pole portion ofthe second magnetic layer is used as a mask to form a trim structure.18. A method of manufacturing a thin film magnetic head as claimed inclaim 17, wherein said etching of the first magnetic layer using thepole portion of the second magnetic layer as the mask is carried outsuch that a part of a thickness of the first magnetic layer is removed.19. A method of manufacturing a thin film magnetic head as claimed inclaim 17, wherein said etching of the first magnetic layer using thepole portion of the second magnetic layer as the mask is carried outsuch that the first magnetic layer is removed over its whole thickness.20. A method of manufacturing a thin film magnetic head as claimed inclaim 13, wherein said step of forming the recessed portion in thesurface of the substrate comprises: the step of forming a photoresistlayer selectively on a part of the surface of the substrate at which therecessed portion is to be formed later; the step of forming a metal ormetal compound layer constituting a mask by a plating, while saidphotoresist layer is used as a mask; the step of forming a mask byremoving said photoresist layer, said mask having an openingcorresponding to the recessed portion to be formed; and the step offorming the recessed portion in the substrate by a reactive ion etchingthrough the opening.
 21. A method of manufacturing a thin film magnetichead as claimed in claim 20, wherein said reactive ion etching forforming the recessed portion is conducted by using, as a reactive gas, afluorine series gas such as CF₄ and SF₆ or a chlorine series gas such asBCl₃ and Cl₂ or these gases diluted with an oxygen or inert gas.
 22. Amethod of manufacturing a thin film magnetic head as claimed in claim20, wherein before forming the mask made of metal or metal compound, aninsulating layer is formed on the substrate, and then after forming therecessed portion by the etching, said mask made of metal or metalcompound is removed by etching while said insulating layer is used as anetching stopper.
 23. A method of manufacturing a thin film magnetic headas claimed in claim 20, wherein said recessed portion is formed to havea depth not less than 5 μm.
 24. A method of manufacturing a thin filmmagnetic head as claimed in claim 20, wherein said recessed portion isformed to have a side wall which is inclined by an inclination angle of45°-75°.
 25. A method of manufacturing a thin film magnetic head asclaimed in any one of claims 13-24, wherein a magnetoresistive typereproducing element for reading is formed on said third magnetic layersuch that the reproducing element is electrically isolated andmagnetically shielded to construct the thin film magnetic head as acombination type thin film magnetic head.
 26. A method of manufacturinga thin film magnetic head as claimed in claim 25, wherein after a firstshield layer for effecting a magnetic shield is formed on the substrateand a magnetoresistive material layer is formed such that this layer isembedded within an insulating layer, said first magnetic layer whichalso serves as a second shield is formed and during the polishingprocess for forming the air bearing surface, said first shield layer aswell as said magnetoresistive material layer are polished to form themagnetoresistive type reproducing element whose end surface is exposedon the air bearing surface.
 27. A method of manufacturing a combinationtype thin film magnetic head having an inductive type writing thin filmmagnetic head and a magnetoresistive type reading thin film magnetichead for reading successively stached on a substrate comprising: thestep of forming a recessed portion in a surface of a substrate; the stepof forming a first insulating layer on an inner surface of the recessedportion as well as on a part of the surface of the substrate; the stepof forming, a first magnetic layer on a surface of said first insulatinglayer; the step of forming a thin film coil within the recessed portionsuch that the thin film coil is isolated by a second insulating layer;the step of forming a gap layer made of a non-magnetic material onsurfaces of said first magnetic layer and second insulating layer; thestep of forming a second magnetic layer on said gap layer such that thesecond magnetic layer is opposed to a pole portion of the first magneticlayer and is brought into contact with said first magnetic layer at aportion remote from an air bearing surface; the step of forming areading magnetoresistive layer on a surface of said second magneticlayer such that the magnetoresistive layer is embedded within a shieldgap layer and is electrically isolated and magnetically shielded; thestep of forming a third magnetic layer on said shield gap layer; and thestep of forming the air bearing surface to be opposed to a magneticrecord medium by polishing said substrate, pole portions of said firstand second magnetic layers, gap layer sandwiched by these pole portions,shield gap layer, magnetoresistive layer and third magnetic layer, whilean edge of the recessed portion formed in the substrate is used as apositional reference; wherein a throat height of the inductive type thinfilm writing magnetic head is adjusted independently from a MR height ofthe magnetoresistive type reading thin film magnetic head by controllinga thickness of said first insulating layer.
 28. A method ofmanufacturing a combination type thin film magnetic head as claimed inclaim 27, wherein the throat height of said inductive type writing thinfilm magnetic head is adjusted while the MR height of saidmagnetoresistive type reading thin film magnetic head is remainedconstant.
 29. A method of manufacturing a combination type thin filmmagnetic head as claimed in claim 7, wherein a thickness of said firstinsulating layer is controlled at will within a range of 0.2-0.8 μm. 30.A method of manufacturing a thin film magnetic head as claimed in claim27, wherein said step of forming the recessed portion in the surface ofthe substrate comprises: the step of forming a photoresist layerselectively on a part of the surface at the substrate at which therecessed portion is to be formed later; the step of forming a metal ormetal compound layer constituting a mask by a plating, while saidphotoresist layer is used as a mask; the step of forming a mask byremoving said photoresist layer, said mask having an openingcorresponding to the recessed portion to be formed; and the step offorming the recessed portion in the substrate by a reactive ion etchingthrough the opening.
 31. A method of manufacturing a thin film magnetichead as claimed in claim 30, wherein said reactive ion etching forforming the recessed portion is conducted by using, as a reactive gas, afluorine series gas such as Cl₄ and SF₆ or a chlorine series gas such asBCl₃ and Cl₂ or these gases diluted with tin oxygen or inert gas.
 32. Amethod of manufacturing a thin film magnetic head as claimed in claim30, wherein before forming the mask made of metal or metal compound, aninsulating layer is formed on the substrate, and then after forming therecessed portion by the etching, said mask made of metal or metalcompound is removed by etching while said insulating layer is used as anetching stopper.
 33. A method of manufacturing a thin film magnetic headas claimed in claim 30, wherein said recessed portion is formed in thesurface of the substrate to have a depth not less than 5 μm.
 34. Amethod of manufacturing a thin film magnetic head as claimed in claim30, wherein said recessed portion is formed to have a side wall which isinclined by an inclination angle of 45°-75°.
 35. A method ofmanufacturing a combination type thin film magnetic head having aninductive type writing thin film magnetic head and magnetoresistive typereading thin film magnetic head for reading successively stacked on asubstrate comprising: the step of forming a recessed portion in asurface of a substrate; the step of forming a first insulating layer onan inner surface of the recessed portion and a part of the surface ofthe substrate; the step of forming a first magnetic layer on a surfaceof said first insulating layer; the step of forming a thin film coilwithin the recessed portion such that the thin film coil is isolated bya second insulating layer; the step of forming a gap layer made of anon-magnetic material on surfaces of said first magnetic layer andsecond insulating layer; the step of forming a second magnetic layer onsaid gap layer such that said second magnetic layer includes a poleportion which is opposed to a pole portion of the first magnetic layerand a rear portion which extends beyond the pole portion; the step offorming a third magnetic layer which is brought into contact with saidsecond magnetic layer as well as with said first magnetic layer at aportion remote from an air bearing surface; the step of forming areading magnetoresistive layer on said second magnetic layer such thatthe magnetoresistive layer is embedded within a shield gap layer and iselectrically isolated and magnetically shielded; the step of forming afourth magnetic layer on said shield gap layer; and the step of formingthe air bearing surface to be opposed to a magnetic record medium bypolishing said substrate, first, second and second magnetic layers, gaplayer, shield gap layer, magnetoresistive layer and fourth magneticlayer, while an edge of the recessed portion formed in the substrate isused as a positional reference; wherein a throat height of the inductivetype thin film writing magnetic head is adjusted independently from a MRheight of the magnetoresistive type reading, thin film magnetic head bycontrolling a thickness of said first insulating layer.
 36. A method ofmanufacturing a combination type thin film magnetic head as claimed inclaim 35, wherein the throat height of said inductive type writing thinfilm magnetic head is adjusted while the MR height of saidmagnetoresistive type reading thin film magnetic head is remainedconstant.
 37. A method of manufacturing a combination type thin filmmagnetic head as claimed in claim 35, wherein a thickness of said firstinsulating layer is controlled at will within a range of 0.2-0.8 μm. 38.A method of manufacturing, a combination type thin film magnetic head asclaimed in claim 35, wherein upon forming said second magnetic layer, awidth of the rear portion beyond the pole portion is wider than a widthof the pole portion.
 39. A method of manufacturing a combination typethin film magnetic head as claimed in claim 38, wherein width of therear portion of the second magnetic layer is gradually increased.
 40. Amethod of manufacturing a combination type thin film magnetic head asclaimed in claim 39, wherein said rear portion of the second magneticlayer is widened by an expansion angle of 30-180°.
 41. A method ofmanufacturing a combination type thin film magnetic head as claimed inclaim 35, wherein after forming said second magnetic layer, the poleportion of said first magnetic layer is etched to form a trim structure,while the pole portion of the second magnetic layer is used as a mask.42. A method of manufacturing a thin film magnetic head as claimed inclaim 35, wherein said step of forming the recessed portion in thesurface of the substrate comprises: the step of forming a photoresistlayer selectively on a part of the surface of the substrate at which therecessed portion is to be formed later; the step of forming a metal ormetal compound layer constituting a mask by a plating, while saidphotoresist layer is used as a mask; the step of forming a mask byremoving said photoresist layer, said mask having an opening,corresponding to the recessed portion to be formed; and the step offorming the recessed portion in the substrate by a reactive ion etchingthrough the opening.
 43. A method of manufacturing a thin film magnetichead as claimed in claim 42, wherein said reactive ion etching forforming the recessed portion is conducted by using, as a reactive gas, afluorine series gas such as CF₄ and SF₆ or a chlorine series (as such asBCl₃ and Cl₂ or these gases diluted with an oxygen or inert gas.
 44. Amethod of manufacturing, a thin film magnetic head as claimed in claim42 wherein before forming the mask made of metal or metal compound, aninsulating layer is formed on the substrate, and then after forming therecessed portion by the etching, said mask made of metal or metalcompound is removed by etching while said insulating layer is used is anetching stopper.
 45. A method of manufacturing a thin film magnetic headas claimed in claim 42, wherein said recessed portion is formed in thesurface of the substrate to have a depth not less than 5 μm.
 46. Amethod of manufacturing a thin film magnetic head as claimed in claim42, wherein said recessed portion is formed to have a side wall which isinclined by an inclination angle of 45-75°.
 47. A method ofmanufacturing a combination type thin film magnetic head having aninductive type writing thin film magnetic head and a magnetoresistivetype reading thin film magnetic head for readings successively stackedon a substrate comprising: the step of forming a first magnetic layer ona surface of a substrate in accordance with a given pattern; the step offorming a recessed portion in the surface of the substrate, while saidfirst magnetic layer is used as a mask; the step of forming a firstinsulating layer and a second magnetic layer successively on an innersurface of the recessed portion; the step of forming a magnetoresistivelayer for reading on said first magnetic layer such that themagnetoresistive layer is embedded within a shield gap layer; the stepof forming a second magnetic layer on said first insulating layer withinsaid recessed portion as well as on said shield gap layer; the step offorming a thin film coil on said second magnetic layer within therecessed portion such that the thin film coil is isolated by a secondinsulating layer; the step of forming a gap layer made of a non-magneticmaterial on said second magnetic layer and second insulating layer; thestep of forming a third magnetic layer which is opposed to said secondmagnetic layer vial said gap layer and is magnetically coupled with saidsecond magnetic layer at a portion remote from an air bearing surface;and the step of forming, an air bearing surface to be opposed to amagnetic record medium by polishing said substrate, first magneticlayer, shield gap layer, magnetoresistive layer, second magnetic layer,gap layer and third magnetic layer, while an edge of the recessedportion formed in the substrate is used as a positional reference;wherein a throat height of the inductive type thin film writing magnetichead is adjusted independently from a MR height of the magnetoresistivetype reading thin film magnetic head by controlling a thickness of saidfirst insulating layer.
 48. A method of manufacturing a combination typethin film magnetic head as claimed in claim 47, wherein the throatheight of said inductive type writing thin film magnetic head isadjusted while the MR height of said magnetoresistive type reading thinfilm magnetic head is remained constant.
 49. A method of manufacturing acombination type thin film magnetic head as claimed in claim 47, whereina thickness of said first insulating layer is controlled at will withina range of 0.2-0.8 μm.
 50. A method of manufacturing a thin filmmagnetic head as claimed in claim 47, wherein said recessed portion isformed by conducting a reactive ion etching, while said first magneticlayer is used as a mask.
 51. A method of manufacturing a thin filmmagnetic head as claimed in claim 50, wherein said reactive ion etchingfor forming the recessed portion is conducted by using, as a reactivegas, a fluorine series gas such as CF₄ and SF₆ or a chlorine series gassuch as BCl₃ and Cl₂ or these gases diluted with an oxygen or inert gas.52. A method of manufacturing a thin film magnetic head as claimed inclaim 51, wherein said recessed portion is formed in the surface of thesubstrate to have a depth not less than 5 μm.
 53. A method ofmanufacturing a thin film magnetic head as claimed in claim 51, whereinsaid recessed portion is formed to have a side wall which is inclined byan inclination angle of 45°-75°.
 54. A method of manufacturing acombination type thin film magnetic head having an inductive typewriting thin film magnetic head and a magnetoresistive type reading thinfilm magnetic head for reading successively stacked on a substratecomprising: the step of forming a first magnetic layer on a surface of asubstrate in accordance with a given pattern; the step of forming arecessed portion in the surface of the substrate, while said firstmagnetic layer is used as a mask; the step of forming a first insulatinglayer on an inner surface of the recessed portion; the step of forming amagnetoresistive layer for reading on said first magnetic layer suchthat the magnetoresistive layer is embedded within a shield gap layer;the step of forming a second magnetic layer on said first insulatinglayer within said recessed portion as well as on said shield gap layer;the step of forming, a thin film coil on said second magnetic layerwithin the recessed portion such that the thin film coil is isolated bya second insulating layer; the step of forming a gap layer made of anon-magnetic material on said second magnetic layer and secondinsulating layer; the step of forming a third magnetic layer which isopposed to said second magnetic layer via said gap layer and ismagnetically coupled with said second magnetic layer at a portion remotefrom an air bearing surface; and the step of forming an air bearingsurface to be opposed to a magnetic record medium by polishing saidsubstrate, first magnetic layer, shield gap layer, magnetoresistivelayer, second magnetic layer, gap layer and third magnetic layer, whilean edge of the recessed portion formed in the substrate is used as apositional reference; wherein a throat height of the inductive type thinfilm writing magnetic head is adjusted independently from a MR height ofthe magnetoresistive type reading thin film magnetic head by controllinga thickness of said first insulating layer.
 55. A method ofmanufacturing a combination type thin film magnetic head as claimed inclaim 54, wherein the throat height of said inductive type writing thinfilm magnetic head is adjusted while the MR height of saidmagnetoresistive type reading thin film magnetic head is remainedconstant.
 56. A method of manufacturing a combination type thin filmmagnetic head as claimed in claim 54, wherein a thickness of said firstinsulating layer is controlled at will within a range of 0.2-0.8 μm. 57.A method of manufacturing a thin film magnetic head as claimed in claim54, wherein said recessed portion is formed by conducting a reactive ionetching, while said first magnetic layer is used as a mask.
 58. A methodof manufacturing a thin film magnetic head as claimed in claim 57,wherein said reactive ion etching for forming the recessed portion isconducted by using, as a reactive gas, a fluorine series gas such as CF₄and SF₆ or a chlorine series gas such as BCl₃ and Cl₂ or these gasesdiluted with an oxygen or inert gas.
 59. A method of manufacturing athin film magnetic head as claimed in claim 57, wherein said recessedportion is formed in the surface of the substrate to have a depth notless than 5 lam.
 60. A method of manufacturing a thin film magnetic headas claimed in claim 57, wherein said recessed portion is formed to havea side wall which is inclined by an inclination angle of 45°-75°.